Production of knitted fabric



Oct. 6, 1936. R. K. MILLS 2,056,686

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PRODUCTION OF KNITTED manic Filed April 11, 1934 '6"Shaets-Sheet 3 Arm/ways.

Oct. 6, 1936. R. K. MILLS 2,055,686

PRODUCTION OF KNITTED FABRIC Filed April 11, 1954 e Sheets-Sheet 4' Fig.8.

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Oct. 6, 1936. R. K.- MILLS 2,056,686 Q PRODUCTION OF KNITTED FABRIC Filed April 11, 1934 I 6 Sheets-Sheet 6 24 27 F1915. H M23 J g+2 A TTOQNE 7 Patented Oct. 6, 1936 PATENT OFFICE PRODUCTION OF KNITTED FABRIC Robert Kirkland Mills, Sherwood, Nottingham,

England Application April 11, 1934, Serial No. 120,105 In Great Britain April 18, 1933 10 Claims. (01. 56-9) This invention relates to improvements in the production of. knitted fabric of the type embodying intermeshing thread loops selected of which are bound or tied one upon another by passing one loop through and around another loop.

Heretofore in this type of fabric-the locking thread loops extend substantially straight between the stitch loops locked thereby. This inevitably reduces elasticity of the fabric in a direction 'at right angles to the wales, while additionally strain on the fabric in the direction of the stitch courses (at right angles to the wales) is taken by the locking thread only and the fabric strength is consequently determined by and limited to the strength of. the locking thread.

Attempts have been made to overcome these disadvantages; for example by tensioning the locking loop thread to a different degree from that applied to the ordinary stitch loop thread. In another example, holding-down sinkers of the kind usually employed in latch needle knitting machines have been given a greater forward movement towards the needles thanis normal, subsequent to the loops of the locking thread being drawn through the loops to be locked, in order to draw or measure the desired length of locking thread around the shanks of the needles; Seeing, however, that the locking thread and also the thread of the loops to be locked both extend through the same throats in the sinkers, this additional forward movement of. the sinkers inevitably exerts a strain on the thread of the previously formed stitch loops to be locked which are carried on the needles, and such strain results in breaking or weakening of said previously formed loops.

, The present invention has amongst its objects to provide a locked fabric of the type referred to wherein the elasticity is maintained without exerting excess strain on, or otherwise adversely affecting, any thread during fabric production,

' and wherein the strength of the fabric (resistance to thread breakage.) is appreciably increased.

I According to the present invention, these and other desirable characteristics are obtained in I a non -ladder or ladder-resisting fabric of the type referred to by the employment of a knitting machine embodying means whereby the two types of thread loops, 1. stitch loops and stitch-locking loops, are drawn or sunk by independent means or elements or by differentwparts of the same means or elements.

5 By virtue of. controlling the draw of the two classes of loop (stitch loops and stitch-locking loops) by different elements or parts, strain upon the loops of either class when drawing the loops of the other class is eliminated, and the possibility of thread breakage during stitch production is minimized; while additionally adjustment or variation of the thread draw for either class of loop is rendered a practical proposition. C0n-' sequently another feature of. the invention resides in the provision of means for variably adjusting the draw of stitch loops and/or stitch looking I loops so as variably to determine the relative length or size of said two classes of loops. This variable adjustment'in the draw of the stitch loops and/or locking loops enables other novel and desirable effects to be obtained in .the type of locked fabric under consideration. For example, the relative lengths of the stitch loops and looking loops can be so determined that the threads appertaining to both types of loop equally share tensile strain in the produced fabric, in which case the fabric strength (resistance to thread breakage) at right angles to the stitch wales is equal to the combined strength of the two threads (stitch thread and locking thread). This enables fabric to be produced which, as compared with lockedmfabric of the same type heretofore constructed, is considerably stronger and more durable without increasing the strength or count of yarn employed; or alternatively a fabric of undiminished strength can be knitted with com. paratively finer or weaker yarn. Also the selective variation of the length or size ofeither the stitch loops or looking loops enables fabric to be tightened or slackened at will; while additionally one ,of the two classes of loops (preferably the locking loops), can be extended to such a size or length as to stand out from the fabric faceand produce a chenille or pile fabric.

The invention is more particularly concerned with latch needle machines, and preferably with the type of machines wherein each or selected of the needles have a plurality of displaceable latches located one below another on the needle stem, there being provided thread feeding means and means for effecting relative movement between the said plural latch needle or needles and thread feed so as to cause a thread loop. to be drawn through and passed around or over another loop so as to tie one loop upon another. The invention is, however, also applicableto machines incorporating means other than plural latch needles for passing one loop through and around another without casting ofl, in the production of the aforesaid fabric.

A further featureof the invention resides in I GI V and controlling a stitch loop to be locked and also with a part above said throat for drawing or measuring a loop of locking thread by which the stitch loop is to be locked or tied; the said stitch loop to be locked being, as is customary, received within the throat as theneedle rises to clear a previously formed loop, and the depth of said throat {the distance to which the throat extends into the sinker) being such as to permit of the required length of locking thread being drawn to ensure elasticity without exerting tension or strain on the previously drawn stitch loop accommodated in the throat.

Preferably, each sinker or instrument is provided with a neb or nose above the throat, which neb serves to separate the locking thread from the loop in the throat and also prevents the locking thread being drawn down into the throat when the needle is lowered to draw a loop of the locking thread through the loop to be locked; it being appreciated that during retraction of the needles loops to be lockedare drawn in the normal manner over the belly or nose of two adjacent sinkers below the throat thereof, while locking loops are drawn over the top edge of the neb above said throat without imparting any strain upon the first drawn loop.

Forthe purpose of more fully describing the nature of this invention reference will now be made to the accompanying drawings, wherein:

Figure 1 is a general elevational view of a circular knitting machine in accordance with the present invention.

Figure 2 shows a portion of locked knitted fabric produced in accordance with this invention.

Figure 3 shows in cross section a modified form of fabric produced in accordance with this invention.

Figures 4 to 12 inclusive show successive steps in the production of fabric according to Figure 2.

Figure 13 shows a sinker member employed in the production of the fabric.

Figure 14 is a detail in perspective showing the operation of the needles and sinkers while producing locked stitches. v

Figure 15 is a side elevational view of part of the machine shown in Figure 1 looking in the direction of arrow X.

Figure 16 is a planof part of Figure 15.

Figure 17 is an underneath plan, enlarged, of part of the sinker cam ring and sinker operating cams at the locking thread feed.

Figure 18 is an enlarged sectional detail of part of the mechanism shown in Figures 1 and 15 for adjusting the sinker cam at the locking thread feed.

part of the mechanism for controlling the sinker cam associated with the locking thread feed.

Figure 20 is a sectional detail showing one method of varying the draw of stitch loops to be v locked.

Figure 21 is a development of the needle-oper- Flgure 19 is another enlarged sectional detail of *FiB. 8).

ating cams for producing ordinary stitches and locked stitches.

In a preferred embodiment of this invention, hereinafter described with reference to a circular latch needle machine, needles I having two latches 2, 3, one below the other, are employed,

which latchesare so spaced that the lower latch 3 when raised abuts against the end of the upper latch 2 when the latter is in the lowered position, so that said upper latch (which is arranged to abut against and close the hook 4 in the usual manner) may be held open by the lower latch. For each such plural latch needle there is a sinker 5 which is movable backwards and forwards between the needles in the usual manner (by means of a butt 6 working in a camtrack) and is provided with a throat I to receive and control the loop which is to be locked, and below said throat with a belly or nose 8 of normal shape; see Figure 13. Above this throat I there is a narrow forwardly projectingneb or nose which has a straight top edge and above and at the rear of this neb 9 there is a part or catch with a vertical edge It), the function of which is to form, divide or measure loops of the locking thread. It is important that the throat I shall be cut deeper into the sinker 5, that is to say extend further back, than the vertical edge I of the catch so that loops of the locking thread may be sunk by the advance of the sinkers without straining the loops to be locked, which are accommodated in the sinker throats 1.

Suitably spaced around th needle cylinder H of the machine are two different types of needleoperating or stitch'cams one 00 for producing ordinary knitted stitches to be locked and the other 10 for producing locked stitches, (see Figure 21). The two types of cams operate in succession upon the needles, and considering the movement of one needle, the successive steps in the production of a locked stitch will now be described with reference to Figures 4 to 12. In Figure 4 the needle is moved by the ordinary stitch cams CC to a position wherein the old stitch loop a is cleared below the top latch 2 and a thread I? is fed into the hook 4, the needle being then lowered to knock over and produce an ordinary stitch b (Figure the length or size of said stitch b being determined by the extent to.

which same is drawn down over the belly or nose portion 8 of the sinker, i. e. by the distance to which the hook 4 passes below the top edge of said portion. During this movement the sinkers 5 (one of which is shown) are retracted in the customary manner by any known or suitable type of sinker cam (not shown). then operated upon by the locked stitch cams LC and is first raised thereby from the normal lowered position until the previously formed stitch loop b is brought on to the raised bottom latch l to the position shown in Figure 6. During this upward movement of the needle I to bring said loop b to this position, the top latch 2 is, of course, swung down and its end therefore overlies the end of the raised bottom latch 3. The needle is then lowered somewhat so that the said loop b (which is to be locked) passes underneath the top latch 2 to the position shown in Figure '7; and next the needle is raised to clear the loop down below the bottom latch 3, by which movement thesaid bottom latch isopened; (see With the needle in this position a thread 0, which may be termed the locking thread, is fed across the needle in the space between the The needle is two latches. above the nebs 9 of the sinkers 5 which are now being advanced between the needles. During the forward movement of the sinkers, the locking thread is engaged and drawn by the vertical edges ll thereof, and the needle is lowered by the stitch cam, during which movement the stitch loop b which is to be locked causes the bottom latch 3 to swing up and to hold. the top latch 2 in its lowered position so that the loop of the locking thread c on the needle is enclosed between the two latches; (Fig. 9). As the sinker loop of the locking thread is held by the angular recess in the sinker neb 9, continued downward movement of the needle draws the loop 0 through the previously formed loop I), which latter passes up over the top latch 2 (Fig. 10) with the result that the said-top latch is swung up by the loop c of the locking thread, (Fig. 11), the sinker meanwhile being retracted. On the final part of the downward movement of" the needle the previously formed loop I) is enclosed in the hook 4, and the loop 0 of the locking thread is cast oil over and around the old stitch loop b which is retained in the hook; see Fig. 12; the sinker having by this time been withdrawn to disengage the loop 0 from the neb 5. By this means along loop is drawn from the locking thread 0, because said loop is drawn over the nebs 9 of the sinkers 5 to each side of any needle I under consideration, while the loop I) to be locked is, during the formation of said loop and during the descent of the needle to draw the locking loop through it, held over the bellies or noses 8 of said sinkers, and as clearly shown in Figs. 9, 10, and 11 is in no way strained while drawing said locking loop.

It will beunderstood that there is a thread feed for each set of cams 0C and DC, (ordinary stitch and locked stitch cams), so that after a.

needle has produced an ordinary stitch at the ordinary cams said needle passes on to the looking cams where said stitch is locked in the manner before-described, and upon subsequent arrival of the needle at the ordinary cams, a normal stitch is drawn '-through the locked stitch and the latter is cast oif.

The above described operations result in a 4 locked fabric of the kind referred -to, in which each of the loops of locking thread c extends when the fabric is relaxed in a curve or loop of substantial length or curvature from thread bar to thread bar of locked loops b, both across the loops and across the wales between said loops,

as shown in Fig. 2, so that such loops incorporate a suihcient length of thread "to permit of the fabric stretching in a normal manner. By virtue of the additional draw imparted to the sinker loops of the locking thread, these loops are somewhat longer or more pronounced in the finished fabric thanthe locking thread stitch loops; this effect being clearly shown in Fig. 2 where c indicates the longer sinker loops and c the shorter stitch loops. I

By virtue of relaxing or lengthening the loops' of locking thread c the strength of the fabric, i. e. resistance to thread breakage under strain, is considerably increased, as by suitably determining the relative lengths of the loops b and c the strength of the thread 0 can be added to that of the thread I). It will be appreciated that this would not be the case if the loops of locking thread c were so tightly drawn as to extend approximately straight across the stitch loops b and the stitch wales, as in the latter case transverse stretch (tension in the direction of the stitch cov' srsl wouldnecessarily first be taken the needles over the locking stitch only by the locking thread c and not by the combined threads b and c as is possible in the present invention. Additionally,'the relaxation of the thread c so that same does not receive the full force of imparted tension permits the employment of a locking thread which is appreciably flner or thinner than the ordinary stitch thread b without in any way weakening the fabric, i. e, without reducing its tensile strength; in fact even with a comparatively thin locking thread, the strength of the fabric is increased as compared with ordinary (unlocked) knitted fabric which is knitted with yarn of the same count as theordinary stitch thread b of a locked tained fully advanced and said group of needles v are also maintained at an equal height immediately prior to the delivery of the drawn or sunk loops from the sinkers to the needles. This ensures a uniform amount of each thread (stitch thread and locking thread) being delivered to each needle and equalizes, the loops of said threads on the needles, thereby also rendering more uniform than heretofore the distribution of the two threads over the needles in knitting a complete course. At the locking thread feed this dwell in the needle and sinkers is provided substantially midway in the downward or thread-drawing movement of the needles. In Figure 14 is shown the operation of the needles and'sinkers at the locking thread feed, and the broken line d illustrates the track traversed by cams during the thread-drawing operation, the position of the dwell" being shown at 11. Where sink ers are employed of the type shown in Figure 13 having a flat topped be required to provide a specially shaped sinker cam with a short straight portion for producing the "dweiP and maintaining a group of adjacent sinkers advanced to a uniform extent during the operation of drawing over said noses the ordinary stitch thread so long as the needle-operating cam is designed to maintain the needle group at a uniform height, i. e. fully lowered, while the thread is being drawn over said noses.

If, however, the sinkers have inclined noses over which the stitch thread is drawn, the sinker cam will be provided with a short straight portion to obtain the required dwell.

As before-stated the length or size of the looking stitch loops relatively to the stitch loops to be locked can be varied without subjecting either set of loops to excess strain; and in this invention means are provided for progressively controlling the sinker displacement at predetermined intervals (e. g. course by course) at the locking thread-feed so as to produce gradual decrease or increase of the .locking stitch size.

Considering for example the manufacture of seamless stockings, it is usual to incorporate means on the machine for gradually tightening the stitches as the knitting proceeds down the leg towards the heel, such operation being known as stiffening; and during this stiffening process the locking stitches are also progressively tightened. gradual adjustment of the sinker cam at the position of the locking thread feed; and one connose portion 8, it may not This is advantageously efiected byvenient method of accomplishing this will now be described. At the end of the main cam drum l2 of the machine (which drum controls the thread feeders and the movement into and out of operative position of-the locking stitch cams in a manner similar to that described in Patent No. 1,977,522, issued to me) is a' ring I 2 having onitarack llof,say,thirtyteethandacam or graduated segment it having a drop of say .030". This ring I3, is freely mounted on the drum l2 but has an axially projecting pin II which is in the track of a radialdriving pin II on the'drum i2. Therefore, as the drum is periodically racked, the driving pin I! will eventually he brought against the pin. it on the ring I! and the latter rotated. This rotation brings the rack it into the range of a pawl it, which is worked from the oscillating quadrant it common to this type of machine, and said movement. is so timed that itoccurs at the time when stiifening is to commerce. Thereafter, the ring I3 is racked independently of the drum i2, step by step, but each step permits a push rod 20 associated with said segment to fall a thousandth "or an inch on the aforesaid cam l5; saidrod being pulled down by a spring 2!. The top end of this push rod 20 is chamfered as at 22 and cooperates with one arm of a centrally pivoted, two-armed lever 23. The other arm of this lever 23, which is provided with an adjusting screw 24, bears against the outer face of one arm of another horizontal centrally pivoted lever 25, which is influenced by a spring 25' pressing-the .two levers 23, 25 together and biasing the lever 23 against the push rod 20. The other arm of" the lever 25 is attached to a radially slidable plate 26 on the sinker ring 21, which plate It carries a cam device serving to withdraw the sinkers, as will hereinafter be described. The withdrawal cam device on this plate 26 embodies-two cam portions 28, 29 spaced apart cir- 30 is moved outwards so that 'the sinkers are pushed inwards to a lesser degree and progressively smaller locking thread loops are drawnas knitting proceeds down the leg of the hose. The

said advancing earn 3. is formed upon a circumferentially extending finger a which ispivoted to the sinker cam-ring 21, and the free end ofsaidflngerisensagedbyoneendofasmallcentrally pivoted bell crank lever 32 the other endof whiehleverbearabymeans ofanadlusting screwrfl, against the outer face of that arm of the aforesaid lever 25 which is attached 'totheslidingplatefl. Thnsastheplateflis I ing provided.

moved in, the free end of the cam-carrying finger ll ismoved out, suitable biasing springs be- Itwillbe appreciated thatslsckeningor lengthening of the locking thread stitches can be accomplished with the same facility as the tight-- eningbycausingthepushrodlltoriseona suitablecaminsteadof fall.

Chenille or pile fabric by lengthening the locking thread loops to-an extent svilicient to produce a pile. One method ofdoingthisisbyorthe throat'linthesinkersiandadvancingsaid sinkers to an increased degree; and if desired the edge ll of the neb O controlling the lockins thread loops may also be provided at a more forward position on the sinkers.

As will be clearly lmderstood from the foregoing, the relative amounts of ordinary stitch thread and locking thread fed per course of stitches can readily be determined to meet particular requirements or produce desired effects; e. g. to ensure that both threads share strain or tension applied to the fabric in the direction of the stitch courses. For instance, when knitting seamless silk stockings on a 3% inch diameter machine employing 348 needles, the ratio of the ordinary stitch thread to the locking stitch thread is advantageously 37 to 38; in other words, 3'7 inches of pure silk-yarn is fed at the ordinary stitch feeder and 38 inches of similar yarn at the locking stitch feeder in each stitch course irrespective of the diameter or count of yarn.

For varying the draw of the ordinary stitch loops any one of several methods may be employed. For example, this may be accomplished by varying the draw or degree of retraction of the needles; or alternatively by varying the extent to which the sinkers are advanced between the needles and designing said sinkers to draw more or less thread in accordance with the degree of advancement. In another arrangement the draw can be varied by imparting a vertical or rising motion tothe sinkers, and one such arrangement is illustrated in Fig. 20, wherein the sinker nose 8 over which the stitch thread is drawn by the needles is downwardly inclined on its under face 21 at its outer end. said face coacting with a horizontal recess 35 at the top of theneedle cylinder. By varying the degree of radial displacement of the sinker at the time of drawing the stitchthread over the nose 8, said nose is moved up or down (i. e. lengthwise of the needles) and the amount of thread drawn is increased or diminished. The sinker cam operating this sinker would preferably have a flat portion for obtaining the well" as before-described, that is to say, for causing a small group of adjacent sinkers to be simultaneously pro jected to an equal extent.

Although in the foregoing description both the ordinary stitch loops and the locking stitch loops are drawn over the same sinker, it is to be understood that separate sinkers' or 1069- dra'wing instruments may be employed for each class of stitch loop; in. which case two sinkers (one to each class of loop) could be 'slidably disposed side by side in one and the same trick in the sinker carrier. For example; a sinker may be employed similarto that described with reference to Fig. 20 functioning to varythe draw of an ordinary stitch loop by-a vertical t' (movement longitudinally of the needles), and an additional sinker may be slidahly ted alongside same and operated to draw or sink a locking threadloop by movementlaterally of the needles. Alternatively,oneandthesamesinkercanbedesignedand operated to draw or sink an ordinary stitch loop by a vertical t and a locking stitch loop by. a horizontal or lateral relatively to the r I claim:--

i. a machine for the lnrbducflon or knitted fabric of the type referred to needles 7 and sinkers co-operatlng toproduce'stitch loop:

m mmand 180 'to mmduoe iloops which embrm :stitch f'loops iandsloek-ror 'itielsame. the stitch-lookilng 100115 by 'the hdvannement no! esinkers between the needles, and said stitch- Llocking kloops being *drawn over .sinker .or elements other than 'ithose :over which :the ssflibchfloopsiareibeingnmwn.

.2. .A :mnemne according ".to claim :1 and iincl udmg means whereby the "degree co! advancement of the s'in'kers Ebe'tween the .sneedles 51s adjustable to very {the length :or size =.o'f Blocking 3100135.

23. A machine according to whim .il mherein the stitch-flocking lloops we ka wn mound rneedles iby tsinkers advancing ibetween zaeid snee- -sin'kers 'iby retraction of the :needles.

4. A machine 'ito KM '11 :means whereby the (size '10! \tbeitwo type! 26 of loop (stitch 3100p and 310015) is 'nrlably'ldetermined.

25.. .A 'Eknlttin: in accordance 0mm 1 aemploy'in :needles ..5D1vobed :One 'xhe'low another on needle loop drawing :eo-opem'flng needle, leading means, menus :l'uncfloniing m @eflecit relative moment between needies and ileed to cause :I ml Llockinl to :he through nnfl gpuaed mounds mreviously ifonned long and lock or tie said loop, means whereby mt :sfltchlocking are ior elements flmenent :mm those which drew loops to be and amenns sine .of stitch-locking is determined.

A cot I. inhrie :0! the xefen'ed to my iflle ot needlesrhnvlngraplurfli'tydhtchespivotedone Tbe'low another on the needle thank, mild production being elected :by "the lanolin; sequential operations, namelyz-Aint storming an ordinary stlteh'by ieedinx flmend nneedle hook'while the needle is projected, the needle to knock over and 2|. loop a :requiredlengthoverthenosesotunkenntelch sideofuidneedlgieedinsloehnsthreldhetween needle hubs, all needle to duw'ailoopntsegdioehngthreednlfllexe- 1811? located above the which 180011107 and ithrend olt mm dates the "amen 58. .A mnchine according? ito claim 1 2100p 'flnher instrumenteeach a throat and n aneb or nose mm, {terminating in an. un- 1 edgepr whlchgptovldes an :mlmlat to drnwnndmeasm'easdooyotand a? J a. v V.

the (sinker menelith to receive In winter of loop in be floopsynndmeansnhetehym' jndu flufim :alve of (at the from me; fm- 'waneement 0! sa'inken, ilocklnz loop through the gprewfious'l'y iloop 

